There are several different commonly used hormonal treatments for breast cancer. You can talk with your doctor to decide if hormonal therapy is for your type of cancer and which one would be best for you: it will depend largely on the stage of your cancer and whether or not you have already been through the menopause.
Modern hormonal treatments can: block your body’s natural oestrogen from reaching cancer cells, OR
stop or lower the production of oestrogen.
By blocking or stopping the production of oestrogen, hormonal treatments can remove the stimulus for the tumour to grow.
Blocking oestrogen from reaching cancer cells
The most widely used hormonal medicine is tamoxifen, an antioestrogen, which stops oestrogen reaching the cancer cells.
Tamoxifen was introduced in 1973. It can be used to treat all stages of breast cancer in women both before and after they have gone through the menopause.
Antioestrogens: Slow down breast cancer growth by attaching to oestrogen receptors on breast cancer cells.
This means oestrogen itself cannot attach to the receptor.
So even though oestrogen is still present in the body, its activity on the tumour is blocked, and it cannot stimulate tumour growth.
More recently another type of antioestrogen, fulvestrant, has become available. This drug blocks the action of oestrogen at the receptor and destroys the receptor on the cancer cell so it can no longer grow. oestrogenFulvestrant is only used for those women who have gone through the menopause.
Stopping or lowering the production of oestrogen
After the menopause
If you have not gone through the menopause, most of your oestrogen is made in the ovaries. After the menopause, the ovaries stop working and a small amount of oestrogen is still made in other parts of the body such as fat, your liver and muscle.
Aromatase inhibitors are a newer type of drug that work by blocking oestrogen production in these other sites of the body. The side-effects of aromatase inhibitors may be more manageable than antioestrogens.
Aromatase inhibitors: A newer class of hormonal therapy that blocks the production of oestrogen in postmenopausal women .
This reduces the total amount of oestrogen in the body and so deprives the tumour of its stimulus to grow.
If you have already been through the menopause and have advanced breast cancer (i.e. cancer that has spread outside the breast to other parts of the body), your doctor is likely to suggest an aromatase inhibitor, either as a first treatment choice or when the disease has stopped responding to tamoxifen.
If your breast cancer is still at an early stage, one aromatase inhibitor, anastrozole, can also be taken as an adjuvant treatment following surgery to remove the tumour. Recently, the largest breast cancer trial ever conducted, including over 9,300 women, has shown that in post-menopausal women with early breast cancer anastrozole is a more effective adjuvant treatment than tamoxifen, and has fewer serious side effects.
If you have advanced breast cancer and it has stopped responding to treatment with tamoxifen or aromatase inhibitors, your doctor may recommend a progestogen. These are drugs that mimic the natural hormone progesterone. However, the exact way in which they work is not currently known.
Before the menopause
If you are a younger woman who has not yet been through the menopause, oestrogen comes mainly from your ovaries. There is now a group of drugs, called LH-RH analogues, which can stop your ovaries producing oestrogen inducing a temporary ‘menopause’.. In the majority of women, when treatment with these drugs is over, the ovaries start to produce oestrogen again. Many women prefer this drug treatment to the alternative of removing the ovaries through surgery or permanently stopping the ovaries from working by irradiation, as it means there is still a chance of retaining fertility.
You can talk to your doctor to decide whether or not any of these medicines are right for you. |